Buffing wheel



p 9- .1. WELHAVEN 2, 74,149

BUFFING WHEEL Filed June 20, 1939 111 tune/1 4.

Patented Sept. 26, 1939 2,174,149 BUFFING WHEEL John E. Welhaven, Chicago, Ill., assignor to Advance Polishing Wheels, corporation of Illinois Ino.,- Chicago, 111., a

Application June 20, 1939, Serial No. 280,051

6 Claims.

, This invention pertains to improvements in buffing wheels and particularly to wheels in which buffing qualities may be controlled by simple and inexpensive means.

In abrading the surface of metal objects, such as castings for example, it is customary to apply relatively coarse abradants by means of a polishing wheel so-called. Subsequently, it is necessary to smooth over scratches that may be left by the polishing wheel and to apply a higher polish by means of a bufiing wheel.

A distinction is made between polishing wheels and bufiing wheels. In polishing wheels, abrading material, such as alundum or carborundum, is

- glued on the peripheral face of the Wheel. The

size of the polishing particle glued on the Wheel is adapted to the depth of indentations, scratches, or blemishes to be removed from the metal. For example with a sand brass casting that cones from the mold in a rather rough condition, the size of the polishing grain first used is so-called No. which is about the size of granulated sugar. When this has accomplished its preliminary polishing a second polishing cycle is efiected by smaller grain abradant glued to the surface of a polishing wheel. Such, for example, is No. grain which is half the size of No. 90 grain. 'Finally, the casting is smoothed by the polishing wheel sufficiently to be in condition for bufiing.

The bufling operation not only takes out scratches left by the final operation of the polishing wheel, but also imparts to the work a high luster. The bufling wheel, however, is of different structure from the polishing wheel. The bufling wheel preferably should comprise a relatively loose peripheral face. This face must retain .abradant material that is generally in the form of a composition composed of fine powder, a binder and a lubricant rather than granular and generally much softer than alundum or carborundum. Such bufling composition is applied to the rotating bufiing wheel face from time to time by the operator. This is in contrast to the polishing wheel of w ch abradant grains are glued on the face of the polishing wheel. For the buffing wheel the operator applies the bufiing composition to the periphery while the wheel is rotating and the composition is taken up by the wheel and held in place until removed by the frictional action of buffing. This composition in commercial practice is usually applied from cakes of suitable size to be held in the operators hand, for example, a cake '7 x 2" x 2".

An object of this invention is to provide a bufiing wheel of suitably open or loose structure at its peripheral face, but also of suiiiciently rigid structure to withstand practical shop operations.

Another object is to provide a buffi ng wheel with some flexibility of structure to adapt it for different buiiing operations, and also to control the 5 rigidity of the wheel over its central portion inwardly from the buiiing peripheral face. An

ator to utilize elements of the wheel according to the varying needs of individual polished. A further object is to structural a bufiing wheel in articles to be simplify the elements of which a buffing wheel is sent preferred This structure is drawing and appended claims.

perspec- Figure 2 shows an enlarged portion of the peripheral face of one form of bufling wheel built up of a plurality of discs constructed according to the present invention and assembled in manner to illustrate the general appli invention;

cation of this Figure 3 shows a structural element comprising radial arms to be embodied within a buffing wheel to impart certain characteristic qualities according to this invention.

In executing the objects of this invention, considerable advantage is gained by pluralityof fibrous discs, between serted radial arms of thicker of a fibrous'nature. Such a wheel for example, say 25 cloth discs I diameter, for example, 15 inches.

assembling a which are inmaterial preferably may comprise, of convenient These discs may be of muslin or of other fibrous material.

Preferably, the interposed radial arms 2 are joined at their centers to form a disc 3 as in the spider or star-like element illustrat The cloth discs I and interposed are then stitched together firmly.

the stitching penetrates through all center to near the outer face. The

ed in Figure 3. 4

radial arms 2 Preferably, the discs from stitching may a be concentric with the wheel or may be spiral.

The stitching, however, is a feature of importance because it serves to control the firmness of the buffing wheel or the density of the that make up the structure. The in cloth elements ore closely the various lines of sewing occur, the more dense is the bufiing wheel.

The material of which the radial arms 2 are composed may conveniently be of canvas or duck and in fact such material is preferred for many purposes because of its firmness combined with its open structure to retain buffing composition. However, for some purposes the interposed arms may be of paper or of cardboard or may be of leather. It must be remembered that in use the buffing wheels are rotated at considerable speed so that there is centrifugal pull. Hence, though open structure discs are desirable for better retention of bufiing powder, the elements of the disc must be strong and be strongly secured in order to resist the disintegrating effect of high speed operation.

It will be observed for example from Figure 2 that the structure prepared according to the invention herein described results in a peripheral bufiing face 4 in which the flexible elements of which the body is built up present a wavy outline 5 circumferentially of the wheel. The interposed radial ribs press the edges of the adjacent cloth or paper discs laterally. This serves in the first place to produce a wavy circumferential outline but it serves further, when taken with the firmness imparted by stitching the elements and when taken with the rigidity of the radial arms as they extend substantially toward the center of the disc, to introduce a smooth firmness or more closely knit structure in the region of the radial arms. Thus as the wheel rotates against metal to be buffed the wavy outline of the buffing face serves to present the buffing composition with continuously varying angularity. This angularlty changes rapidly. But in the portions between adjacent radial arms there are looseness and relative depth that retain considerable buffing composition against the working face of the metal and thus impart what may be determined a softer buffing action. Yet as the wheel moves onward to present to the metal the portions near the radial arms, the abrading action is somewhat harder. The angularity of buffing is changed suddenly where the discs are expanded around the insert arm. Thus the buffing action may be designated as harder Where the angular or cross-buffing occurs as the cloth discs are held relatively compactly near the arms. As the wheel is rotated there is rapid alternation of soft action and harder action combined with rapidly changing cross polishing or cross angles of contact between buffing powder and the work. 7

With buffing elements of the sort described and provided with a central bore, the operator may build up a composite buffing wheel to suit individual requirements. He is able to place the individual elements on a buffing wheel spindle with considerable rapidity. He may place several such wheels side by side, perhaps as many as 10 or 14. A portion of the peripheral face of such a composite buffing wheel is shown in Figure 2. One quickly disposes adjacent discs so that their radial arms occur out of cross alignment with each other. He may interpose different discs of different materials, for example, some of paper and some of cloth, some having canvas radial arms and some having paper or leather radial arms and thus adapted to receive bufiing composition to different degrees and to apply it with different effects of bumng quality.

While a composite disc may be built up by an operator from discs having only one series of radial arms inserted, it is intended under the present invention to include also a plurality of inserted arms within a given disc and stitched firmly to the adjacent cloth elements. Whether the radial arms are inserted separately or whether several discs are inserted, it is preferable that the radial arms be stitched in staggered relation to each other.

In use, bufling discs of the present invention have exhibited superior buffing quality with considerably reduced cost per unit. For example, a series of 500 bumper bars for automobiles were buffed before wearing out a cloth buffing disc containingcanvas radial inserts, whereas without the radial inserts the same discs buffed only half as many of the bumper bars before wearing out. Hence, there was an improvement of 100% in life with consequent reduction of cost by one half.

While I have illustrated this invention by reference to the best application now known to me of the problems of this invention, it is now evident that those skilled in this art will be able to introduce deviations from the specific illustrative embodiments herein set forth, but within the scope of the appended claims.

What I claim is:

1. A bufiing wheel comprising a plurality of discs of soft sheets secured together with exposed edges forming a soft peripheral face, and inserts of firm fibrous material interposed discontinuously in the peripheral face.

2. A buffing wheel comprising a plurality of discs of soft sheets secured together with exposed edges forming a soft peripheral face and inserts of firm fibrous material interposed as radial arms disposed around the discs and exposed at intervals at the peripheral face.

3. A buffing wheel comprising a plurality of discs of soft sheets secured together centrally with exposed edges forming a soft peripheral face and radial arms of canvas interposed for exposure at intervals at the peripheral face.

4. A buffing wheel comprising a plurality of discs of soft sheets secured together centrally with exposed edges forming a soft peripheral face and interposed discs concentric with the softer discs and comprising radial arms extending for exposure at the peripheral face.

5. A buffing wheel comprising a plurality of discs of soft sheets secured together centrally with exposed edges forming a soft peripheral face and a plurality of concentric discs of fibrous material more dense than the soft discs and disposed in spaced relation to each other and presenting staggered radial inserts in the peripheral face.

6. A buffing wheel comprising a plurality of discs of soft sheets secured together centrally with exposed edges forming a soft peripheral face, and interposed discs concentric with the softer discs and comprising radial arms extending for exposure at the peripheral face, the interposed radial arms being secured by stitching to the adjacent cloth discs.

JOHN E. WELHAVEN. 

